I have a pulled head stud on a Subaru EJ25 and I need some advice.
Current route I plan to take is to have a machine shop helicoil the bad stud.
I'll then use an ARP stud kit instead of threading the OEM bolts back in.
What does everyone think? Will it hold?
This is for my daily appliance 2000 Subaru Forester N/A.
Personally for something like this, I would use a Time-Sert. It is like a Heli-Coil, but on steroids.
Brian
If the machine shop does its job well, there will be no problem. They'll know to keep the insert and threads square with the world; it will last at least as well as the stock bolts.
OTOH, if you turbo it and bump the boost to 45#, don't come cryin' to me! 
I like this idea.
Regular kits on Amazon look reasonable. This might come together after all.
Yes, Time-sert is what you want. They're holding the exhaust manifold in place on my rallycar.
A helicoil is better than the original thread, and very simple to install No need to over think it.
I am with Zomby woof on the helicoil, it is fine for a NA daily. Timesert = magnesium porsche case or a race car. You don't need the shop, its a do it your self project.
+3 on Helicoil. Most alum aircraft parts have helicoils in them. Timeserts are great for parts where the hole has become to big for helicoils due to bad removal of the broken OEM.
Weellll, OK, but the helicoils pulled right out, and we replaced em with timeserts.
Helicoils definitely have a tendency to pull out sometimes.
Keenserts are not particularly expensive and I've had absolutely awesome luck with them. I think McMaster Carr has them. Nicest part about the keenserts is that they go in w/o any special tools (just a drill, tap and a screwdriver or allen key). Downside is they need a bigger hole than a helicoil does.
Helicoils, if properly done, definitely DO NOT have a tendency to pull out. If yours are pulling out, you have something wrong
is that an aluminum block? HTS-2000? youtube it
Zomby woof wrote:Helicoils, if properly done, definitely DO NOT have a tendency to pull out. If yours are pulling out, you have something wrong
No doubt, but I'll take foolproof and reliable over foolvulnerable and reliable, because I'm a fool.
Pumpkin Escobar wrote:is that an aluminum block? HTS-2000? youtube it
i just saw that video a couple weeks ago and holy crap does it look impressive! have you used it yet?
no, but I have A LOT of ideas!
Being a machinist in the aerospace industry I'd be comfortable with a helicoil. If properly installed they are stronger than a regular tapped hole. Basicly the same as a rolled thread bolt is stronger than a cut thread bolt. Now if you like overkill go with a keensert. It's like the Timesert only with keeper tangs. The car will rust to nothing and zombies will take over the earth before a keensert will come out.
Just finishing the thread.
I used the Timesert. There was no way to thread a helicoil 3" down into the block.
You have to file/grind the flange off the end of the timesert. That's used for flush holes and if you leave it on it will get stuck part way down the tapered hole (thanks Subaru!).
Instead of using the Timesert insert tool you have to use an old head bolt. That will allow you to drive that insert down into the hole without having the end expand too soon. Mark the end of the head bolt so you know how far in it needs to go. Finish up with the Timesert insert tool which will expand the end of the insert "locking" the new thread into place. Really neat design but not perfect for a Subaru block.
Timesert part number is 1112 (M11X1.25) and it was $100 on Amazon.
